Cannabinoids, ingested or smoked, are subject to complex biotransformations in man. Approximately two-thirds of the metabolized material is excreted via the feces, while one-third is eliminated ith the urine. The chemical nature of the urinary and fecal metabolites is very different. Numerous polar, carboxylic acid derivatives constitute the bulk of the urinary drug derivatives, while fewer and less polar cannabinoids are characteristically seen in the feces. It is proposed to fractionate the drug content from biological material (human or primate) using XAD-2 columns and selective eluants, to characterize the major individual metabolites (or groups of closely related compounds), and to devise new and extremely sensitive assay procedures by spectrophotofluorometry, thin layer chromatography, gas chromatography/mass spectrometry and liquid chromatography. New automated procedures by direct, multiple-mass fragmentography, requiring little or no sample preparation, will also be explored and algorithms for fully automatic computerized programs will be developed. These will be of two kinds, i.e. qualitative to detect the presence or absence of individual cannabinoids and metabolites, or quantitative, assaying the quantities of individual compounds present.